Rod-packing.



No. 728,124. I PATENTED MAY 12, 1903. J

T. W. MITCHELL.

v EDD PACKING.

APPLICATION FILED MAR. 28, 1901.

N0 MODEL.

Patented May 12, 1903.

FFICE.

ATENT THOMAS W. MITCHELL, OF OMAHA, NEBRASKA.

ROD-PACKING.

SPECIFICATION forming part of Letters Ilatent No; 728,124,-dated May'1 2, 1903.

Application filed March 28,1901. Serial No. 53.240. (No model.)

T0 at whom it may concern; I

Be it known that I, THOMAS IV. MITCHELL, a citizen of the United States, residing at Omaha, in the county of Douglas-,fitate of. Nebraska, have invented certain new and'use ful Improvements in Rod-Packing; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawing, forming a part of this specification, and to the letters of reference'marked thereon. v

This invention relates to improvements in rod-packing, and is designed more especially with a view to the successful packing of the rods of ammonia-compressors orice-machines or machines of like character where noxious" gases are handled or where the machines are subjected to sudden or extreme variations of temperature, the invention having for its object, primarily, to guard against possible escape or loss of any of the gases being compressed and regardless of the variations in temperature to whichthe rod and connected" have an extended contact with the rod, but a 7 narrow or restricted engagement with the fixed portion of the packing, whereby said rings are allowed to assume the temperature of the rod regardless of the temperature of the inclosing casing and, further, whereby the gases may pass around outside of said packing-rings to further aid in maintaining their temperature and the temperature of the rod uniform.

The invention further consists in certain novel details of construction and combinations and arrangements of parts, all as will now be described, and pointed out particularlyv in the appended claims.

The accompanying drawing is a vertical section through a packing for the rod of an ice-machine embodying my present improvements, the oil-circulating system and returnpipe of the compressorbeing shown diagrammatically.

The letter A indicates the head of a compressor-cylinder h-avingca'stuffing-box B, provided with an aperture forthe passage of the usual compressor-rod O. In the preferred construction the stuffing-box B has a cylindrical chamber therein surrounding the rod, and in this chamber two sets of packing-rings 1D and E are mounted, separated slightly from each other, and between them an oil-chamber is formed for the reception of a lubricatipg'and absorbing body of oil which is supplied through a branch pipe G; as will be presently explained. The stuffin'g-box B is closed by a cap 13, which also serves to hold thepacking-rings in-place, for which purpose suitable retaining-rings" HH Il areprovided, said retaining-ringsfitting within the gland and around the ma, In the retaining-rings H and H recesses'are formed for the reception of springs h, which'serve'to hold'the packingrings D and'E together and seat them against the supportingffiange orseat Llocated on the side of the :retaining-ringsaway from the compress'or-cylinder. The packing-rings and the seats I are located in chambers, and the onlyconnection between said rings and seat and the walls of the chambers is formed by a relatively narrowannulus 'K,located on the side of thepacking-rings awayfrom' the compressor-cylinder. The seat Lxwith its supporting-annulus K, eflfectually bars the passage of any oflthe gasesfroln the outside of the packing-ringspwhile the rings themselves barthe passage of any gases along the surface of the rod andbetween the rings. This construction permits said ringsfto change their temperature practically in accordance with the changes of, temperature,whichpccur in the rod itselfand }in the gas'or liquid which is in 'the-compressor-cylinder, for it will be observed that the packing-rings having extended contact withsaid rod and any gases that pass out along said rod will pass outside of the packing-rings or into the chamber surrounding said rings and impart-its temperature to the rings, and because of the very small quantity of metal uniting the rings and body of the stuffing-box or which contacts with the body of the stuffing-box the temperature of the rings is controlled only to a slight extent by the tem perature of the stu [ting-box itself.

As before stated, a chamber F is formed between the packing-rings D and E, and the oil is supplied to this chamber through a branch G of a pipe L, constituting a portion of a circulating system which includes a pump L, a tank L and a return-pipe L The return-pipe L preferably leads from a secondary or expansion packing which is located outside of the main packing and preferably held in place by a secondary cap 15*, carried by the main cap B of the stuffing-box. This secondary packing contains packing-rings M of any approved type, and the chamber surrounding said packing-rings and extending in around the rod at the inner side of said packing-rings is in communication with the pipe L through a branch pipe Z, and the return-pipe L leads directly from said chamber, as shown. The return-pipe L preferably opens into the upper end of the tank L through a check-valve 0, set to prevent any backward movement of the oil or the entry of gas into the pipe L and preferably set so as to maintain a pressure in said pipe L sufficient to prevent the expansion of the gases which may have been absorbed by the oil and which if allowed to expand might congeal the oil, and so arrest the circulation. In front of the discharge-valve O and within the tank L a spreader or separator P is preferably located, so as to spread the oil into as thin a film as possible as it is discharged in order to facilitate the expansion of gases which may be held by said oil, as will be presently explained.

The letter Q, indicates the return'pipe of the compressor system of an ice-machine or ammonia-compressing apparatus, and the tank L is preferably in direct communication with said return-pipe Q through a small pipe q. Thus any gases accumulating in the tank L find ready egress and pass into the general circulating system of the compressing apparatus.

In operation, now, the rod 0 is kept lubricated by the oil in the respective Oil-chambers, and any gas which may find its way struction and should be adjusted to prevent.

the opening of the valve save when the pres sure within the pipe L equals or exceeds the pressure within the tank A or in the returnpipe Q, which determines the pressure within the tank. Obviously the pump L may be operated to give any desired pressure; but the pressure indicated has proven to be effieient and to accomplish all of the desired ends.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is I 1. In rod-packing for compressors the combination with the stuffing-box, the rod passing through the stufling-box and the packingrings surroundingsaid rod within the stuffingboX, and a support for said packing-rings located on the side thereof away from the compressor-cylinder and having a narrow wall forming the connection between said support and stuffing-box whereby the packing-rings may be surrounded by gases and conform to the temperature of the rod; substantially as described.

2. In rod-packing for compressors, the combination with the stufiing-boxhaving the packing-rings therein and intermediate oil-chainber, of a second independent oil-chamber in said stuffingbox, pipes connecting said oilchambers and a circulating system of pipes communicating with said oil-chambers and means for maintaining the circulation of oil in said pipes; substantially as described.

THOMAS N. MITCHELL.

Witnesses:

GEO. F. KING, A. L. Fnos'r. 

